Coquitlam data projectWhich Coquitlam walks are under 2 km and have washrooms? Let Python choose
The City of Coquitlam publishes a layer called Walking Jogging and Hiking Routes. It holds 12 routes, and its distances are stored as text, so a program has to turn them into numbers first. The results below are our own run on the file downloaded 22 October 2026.
The 12 routes in the City of Coquitlam Walking Jogging and Hiking Routes layer, as the file records them (downloaded 22 October 2026), shortest first| Route (NAME) | DISTANCE as written | GRADE | WASHROOMS |
|---|
| Mundy Lake Loop Trail | 0.6km | Flat | Yes |
| Como Lake Loop Trail | 1.0km | Flat | Yes |
| Complex Loop | 1.15 km | Flat / Minor Grade Change | Yes |
| Stadium Loop | 1.2km | Flat / Minor Grade Change | Yes |
| Lakeside Loop | 1.2 km | Flat | Yes |
| Coquitlam Crunch Trail | 2.1km | Steep | No |
| Town Centre Perimetre Trail | 2.7 km | Flat / Minor Grade Change | Yes |
| Hoy Creek Linear Park Trail | 2.8 km | Flat / Minor Grade Change | No |
| Mundy Park Perimeter Trail | 4.0km | Flat | Yes |
| DeBoville Slough Dike Trail | 4.1km | Flat | No |
| Mundy Park Community Trail | 5.6 km | Flat / Minor Grade Change | Yes |
| Coquitlam River Trail Loop | 5.7 km | Flat / Minor Grade Change | No |
Look at the DISTANCE column: half the values are written like 0.6km and half like 1.15 km, with a space. Python cannot compare either with 2.0 until it is cleaned. Our program does that in a two-line function, then answers questions with a second function whose options have default values:import json
def km(text):
return float(text.lower().replace("km", "").strip())
def pick_walks(routes, max_km, need_washroom=False, flat_only=False):
chosen = []
for r in routes:
if km(r["DISTANCE"]) > max_km:
continue
if need_washroom and r["WASHROOMS"] != "Yes":
continue
if flat_only and r["GRADE"].strip() != "Flat":
continue
chosen.append(r["NAME"])
return chosen
with open("walking-routes.json", encoding="utf-8") as f:
routes = [item["attributes"] for item in json.load(f)["features"]]
print(sorted(km(r["DISTANCE"]) for r in routes))
print(pick_walks(routes, 2.0, need_washroom=True))
print(pick_walks(routes, 5.0, flat_only=True))
Text to number
km() lowers the text, removes “km”, strips spaces and calls float(). Run on all 12 rows it prints 0.6, 1.0, 1.15, 1.2, 1.2, 2.1, 2.7, 2.8, 4.0, 4.1, 5.6 and 5.7.
Under 2 km with washrooms
pick_walks(routes, 2.0, need_washroom=True) returns Stadium Loop, Lakeside Loop, Como Lake Loop Trail, Complex Loop and Mundy Lake Loop Trail: five routes, in the order the file stores them.
Flat and up to 5 km
pick_walks(routes, 5.0, flat_only=True) returns five routes too, including the DeBoville Slough Dike Trail at 4.1 km. It leaves out every route marked Flat / Minor Grade Change, because the test asks for exactly Flat.
The trailing space
The Coquitlam Crunch Trail's GRADE is stored as Steep followed by a space. Without .strip(), a test for the word Steep would miss it. Students find that bug by printing repr() of the value, which shows hidden spaces, and it teaches them to distrust a match that silently fails.
The extension task is a judgment, not code: should flat_only accept Flat / Minor Grade Change, and who decides? Students write the rule in a comment before they change the test. The file is used under the Open Government Licence - Coquitlam. Contains information licensed under the Open Government Licence - Coquitlam (licence, City of Coquitlam open data). The City does not endorse this page or our classes, and the list is not advice on trail conditions.
